Fature的作用是异步获取结果，不影响主线程执行，以下是代码

package com.lujiawei.thread;import java.util.concurrent.Callable;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.Future;import java.util.concurrent.FutureTask;public class UserFature implements Callable
    
      {		private int age;		public UserFature(int age) {		this.age = age;	}	@Override	public Integer call() throws Exception {		for(int i=0;i<10;i++){			Thread.sleep(1000);			age = age + 1;			System.out.println("age --> "+age);		}		return age;	}		public static void main(String[] args) throws Exception {		int age = 10;				UserFature userFature = new UserFature(age);		FutureTask
     
       futureTask = new FutureTask<>(userFature);				ExecutorService newFixedThreadPool = Executors.newFixedThreadPool(1);		Future
       f = newFixedThreadPool.submit(futureTask);		System.out.println("直接返回");		System.out.println(f.get());//当返回结果的时候f.get()为null		System.out.println("age为-->"+futureTask.get());	}}
     
    

打印结果为

直接返回age --> 11age --> 12age --> 13age --> 14age --> 15age --> 16age --> 17age --> 18age --> 19age --> 20nullage为-->20